ICF WINDOW CILLS

sandyland

This is the second time I've posted this but I'm pretty sure I posted it in the wrong place the first time,(the Help Desk) so apologies and here goes again.

New to the forum and looking for a little advise. I am well on with a <SNIP> self build and it's all poured and I'm looking at my pile of concrete cills and after reading various posts on the forum regarding problems with water ingress around cills am now wondering would anybody know of any reason why I can't abandon my concrete cills and just fit UPVC windows with UPVC cills already attached. I have fitted many UPVC windows back in the UK and I know you can order them with or without cills, and the cills are available in a number of widths to suit construction. Is there any reason I can't use UPVC cills with an ICF build and if so has anyone any advice on their installation?
Thank you in anticipation.

Poor Uncle Tom

There is no reason why you can't use uPVC cills with the windows. Just, obviously inform the window company when they are measuring up for the windows as I think the windows are deeper and the uPVC cills are shallower then the concrete ones.

I just used standard concrete cills, wrapped in DPC as shown in the manuals and have had no problems at all.

The only thing I did different was to "hang" them in front of the concrete core on a couple of heavyweight brackets and have the windows also on the outside of the concrete core, why - well, no cold bridges!

braftery

Hi there,

I would recommend using Aluminium cills. There are cills systems that come in lots of various depths or you can get pressed metal ones made to order by alot of alu roof construction people. These can all be made in any RAL colour.

If you use system cills they come with special ends depending on the type of external finish you are using (plaster, stone, timber cladding). If you use the pressed metal type, I would recommend getting the ends turned up and welded.

If you go with either uPVA or Alu cills it is important to talk with you window supplier. They need to supply your windows with a different bottom profile in order for you to fix the cills to the window.

I do not supply cills but can pass you on suppliers info, PM me directly.

sandyland

Thanks for the replies Guys and sorry for not getting back to you sooner but have been away over the water for a few days. Will certainly take all your recommendations on board before making any final decision but in the meantime any further advice would be very much appreciated. Thanks